Overview
- Sebastián Báez defeated Jaume Munar 6-4, 6-4 in Perth to secure the opening point for Argentina.
- Solana Sierra beat Jessica Bouzas Maneiro 6-4, 5-7, 6-0 to clinch the tie with a decisive third set.
- Guido Andreozzi and María Lourdes Carlé completed the sweep by topping Íñigo Cervantes and Yvonne Cavalle-Reimers 7-6 (8-6), 6-2 in mixed doubles.
- Argentina next faces the United States in Group A, with Taylor Fritz and Coco Gauff leading the defending champions in a matchup likely to shape quarterfinal qualification.
- The United Cup runs January 2–11 in Perth and Sydney with three-match country ties, up to 500 ATP/WTA ranking points and more than $11 million in prize money.